The Johor River Water Works Upgrade Project
A critical treatment plant upgrade ensuring higher standards of water quality for Singapore
ClientSingapore's Public Utilities Board
Project DurationCommenced: 2008
Service Lines/Product Description
LocationKota Tinggi, Malaysia
Johor River Waterworks (JRWW) situated in Malaysia, is a critical treatment operation being the largest supply source of potable water to Singapore. JRWW extracts water from the Johor River upstream of the town Kota Tinggi, and has three water treatment plants A, B and C, providing a total output of 946 million litres per day (250 million gallons per day).
Plants A and B were designed and constructed by UGL from a period between 1986 to 1999 and used conventional coagulation, clarification, sand filtration and chlorine disinfection as its main treatment processes. Plant C was commissioned in 2001 and uses a more advanced ozonation and biological filtration on top of conventional water treatment.
World Health Organization standards stipulated new requirements for the removal of cryptosporidium from drinking water. Using ultraviolet (UV) disinfection systems and an enhanced filter backwash system, plants A & B of the JRWW operation were upgraded to radically improve water quality and to achieve higher rates of cryptosporidium removal.
UGL was awarded a contract to upgrade the existing JRWW for the Public Utilities Board (PUB), Singapore’s national water agency.
As a geographically small country with high population density, Singapore has much less tolerance for failure in essential services such as water supply. The PUB therefore adopts a zero-tolerance approach and stays ahead of international standards in water quality control and treatment technology.
The latest World Health Organisation (WHO) and US Environmental Protection Agency (EPA) standards specified more stringent requirements on the emerging waterborne disease including cryptosporidium.
The upgrade works at JRWW drew on UGL’s extensive experience in delivering unique water engineering infrastructure solutions throughout South East Asia. The upgrading works were completed with key performance targets met and minimal disruption to existing operations including the plants hydraulic performance. The project continues a long standing relationship of providing services and solutions to the PUB, a highly valued client to UGL.
UGL’s scope of work in delivering this solution included project management, detailed design, procurement, skid fabrication and assembly, transport and logistics, site construction management, health and safety management, environmental management, testing and commissioning.
The solutions scope included:
- Installation of ultraviolet (UV) disinfection systems to achieve at least 4 log inactivation of cryptosporidium
- Upgrade of existing sand filtration backwash and related processes such as filter control and chemical dosing to achieve filtered water turbidity of less than 0.15 NTU (Nephelometric Turbidity Units) in at least 95 % of the measurements each month and at no time exceed 0.3 NTU
- SCADA network enhancement to optimize water treatment plant automation strategies
- Supply of the control panels required for the filtration and chemical systems
- Process testing and commissioning for the filtration and chemical system
- Enhanced filter backwashing and additional treatment processing using UV disinfection to achieve at least 99.9997% removal (5.5-log removal) of cryptosporidium and filtered water turbidity of less than 0.15 NTU
Key Outcomes and Benefits
By implementing UGL’s solution, the PUB was able to generate the quality of treated water required by the World Health Organisation and current US EPA standards.
Through close liaison with the PUB, UGL’s design team were able to identify problem areas in the existing plant and assisted the customer to enhance operational performance. For example, lime slurry D-Mixer maintenance was reduced by increasing the D-Mixers shaft diameter. This eliminated warping of the shaft and general wear on the mechanical seal that had hampered performance of the original D-Mixer installation.
Key outcomes included:
- Improved plant reliability and higher standards in water treatment quality through proven technologies and robust engineering systems
- An innovative system design that made it possible to retrofit ultraviolet disinfection units and static mixers into an existing hydraulic system without reducing plant flow
- Successfully delivering a cost effective solution for improving filter backwash performance by retrofitting a system to permit combined air-water washing into an existing separate air-water wash filter floor
- A significant reduction in plant operation interruptions through close coordination and cooperation with the PUB and UGL’s site management team
- Designing a fit for purpose system that satisfied the customer’s requirements where operational performance exceeded expectations